JPH04175753A - Photosensitive resin composition material for color filter - Google Patents

Abstract

PURPOSE:To obtain a color filter which has a short production process, can be developed with water, and has high precision and high durability by containing novolak resin, a photo-active fusion restrainer, a dye and a solvent. CONSTITUTION:A photosensitive resin composition material is coated on a substrate made of glass with a spinner and the like, it is heated and dried to remove a solvent, a negative mask is put on a coated film on the substrate and radiated with light, it is treated with a developer containing an alkali agent to wash off the unhardened section, and it is washed with water and dried to obtain a color filter. Novolak resin polymerized/condensed with a phenol component containing bisphenol A 50 mol.% or above and an aldehyde component, a photo-denaturated fusion restrainer, and a dye soluble in the solvent and compatible with resin are contained in alkali-soluble resin. The process is shortened, development can be performed in an aqueous solution, high precision and excellent durability are obtained, and no acid is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to resin compositions, and more particularly to transparent colored images colored with dyes for optical applications such as color liquid crystal displays, charge-coupled devices, color sensors, etc. The present invention relates to a photosensitive resin composition used for forming filter pixels.

Conventional technology color filters have R, G, and B on transparent substrates such as glass or plastic, or opaque substrates such as silicon.
Manufactured by forming three primary color elements or Y, M, C three primary color elements.

Color filter manufacturing methods include dyeing methods, electrodeposition methods, printing methods, and the like. However, the dyeing method has the drawbacks of not being able to obtain high-definition products, and of having a long process and poor durability (heat resistance, weather resistance, moisture resistance).

The electrodeposition method has a problem in terms of driving the liquid crystal because a color filter is constructed on the electrodes.

The printing method is an application of existing printing methods, and although it has the advantage of being inexpensive, it also has drawbacks, such as poor surface smoothness due to ink shortages and limited high-definition patterns.

A new method using a pigment-containing resin was introduced in Japanese Patent Laid-Open No. 1-152449.According to this technique, acid is generated in the photocuring part, which poses problems for electronic parts such as corrosion and malfunction of the liquid crystal part.

JP-A-2-127602 discloses a method of manufacturing a color filter using a positive composition containing a dye. This method is advantageous in that the process is short and dyes with excellent spectral properties can be used, but it also has problems such as coloring of the novolac resin and poor developability due to the use of a large amount of dye.

Problems to be Solved by the Invention The above-mentioned problems of the prior art have been solved, that is, the process is short, development is possible with an aqueous solution, high definition and excellent durability, and there is no generation of acids. There is a need for the development of color filter forming technology that can produce color filters that can be used as electronic components without problems.

Means for Solving the Problems The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have arrived at the present invention.

That is, the present invention provides (A) a novolak resin obtained by polycondensing a phenol component containing 50 mono-0 or more bisphenol A and an aldehyde component as an alkali-soluble resin, (B) a photo-modified dissolution inhibitor, (C) a solvent for (D) The present invention relates to a photosensitive resin composition for forming a color filter, which contains a dye (D) that is soluble in (A) and compatible with (A) a resin.

The resin composition of the present invention will be explained in detail.

(A) The alkali-soluble resin component is a binder (binding agent)
(1) The function of uniformly applying the composition onto the substrate; (2) The function of dissolving the composition in water and washing it off from the substrate when developing the composition in the exposed area with an alkaline aqueous solution after exposure. It has two abilities.

It is important to choose whether there are various known compounds such as inoic acid resins, (B) photoactive dissolution inhibitors, especially large amounts of (C) dyes, as the dissolution inhibitory effect changes greatly when the ingredients are mixed. .

Furthermore, for the purpose of forming a color filter, clarity is naturally required, and the resin itself is required to be free from coloration.

In the present invention, the alkali-soluble resin used is a novolac resin obtained by co-condensing a phenol component containing 50 mol% or more of bisphenol A and an aldehyde component, preferably in the presence of an acid catalyst.

Examples of the phenol component to be co-condensed include phenol, 0-cresol, m-cresol, p-cresol, 0-ethylphenol, m-ethylphenol, nol, p-ethylphenol, O-butylphenol, p-
tert-butylfuconol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,
4-xylenol, 3.5-xy 1.・Noll, 2.3
．． 5-)-limethylphenol, p-phenylphenol, hydroquinone, catechol, resorcinol, 2-
Examples of the aldehyde component include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, and benzaldehyde.

In carrying out the co-condensation, the aldehyde is used in a proportion of preferably 0.7 to 3 moles, particularly preferably 0.7 to 2 moles, per mole of the phenol.

As the acid catalyst, for example, inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, or organic acids such as formic acid, oxalic acid, and acetic acid are used.

As a medium in the polycondensation reaction of phenols and aldehydes, water, a mixture of water and a hydrophilic solvent, or the above-mentioned acids are used as the medium. The temperature of the polycondensation reaction is usually 10~
200°C, preferably 70-150°C.

After the reaction is completed, the novolac resin used in the present invention can be obtained by pouring it into water and filtering the precipitate.

(B) Photo-modified dissolution inhibitor is a substance that, when dissolved in (A) alkali-soluble resin, exhibits the property of suppressing alkali solubility and promoting structural change due to light, thereby eliminating or accelerating the dissolution effect. Typical compounds of (B) include quinonediazide compounds, specific examples of which include 1,2-naphthoquinone-2-diazide-5
-Sulfonic acid, 1,2-naphthoquinone-2-diazide-
4-sulfonic acid and low molecular weight aromatic hydroxyl compounds, especially hydroxybenzophenones (e.g. 2,3°4-
Examples include esterification products with trihydroxybenzophenone, 2.3.4.4'-tetrahydroxybenzophenone) or trihydroxybenzenes (for example, 1.3.5'-tetrahydroxybenzophenone). Among these, 1,2-naphthoquinonediazide- which is an ester of 1,2-naphthoquinone-2-diazide-5-sulfonic acid and 2.3.4-)lyhydroxybenzophenone
5-sulfonyl triester is particularly preferred.

Component (C) is a dye serving as a coloring agent that colors the photosensitive resin and configures the pixels of the color filter to have different colors.

This dye must be soluble in the organic solvent (D) and compatible with the resin.

These dyes include, for example, color index C,
1,5olvent Co1our, and a specific example is BASF's Neo.
There are zapon dyes and Kayaset dyes made by Japanese condiments. These dyes are R, G, B or Y, M,
In order to constitute a color filter of three primary colors such as C, it is preferable that the solid content of the photosensitive resin composition of the present invention is 10 to 50%. If it is less than 10%, sufficient optical density cannot be obtained, and if it is more than 50%, transparency tends to decrease.

Component (D) is an organic solvent component, (A), (B),
It is a solvent for component (C) and a dispersion medium. Preferred solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; Diethylene glycol dialkyl ethers such as butyl ether; ethylene glycol alkyl acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol monomethyl ether acetate,
propylene glycol monoethyl ether acetate,
Examples include propylene glycol alkyl ether acetates such as propylene glycol propyl ether acetate.

These solvents may be used alone or in combination of two or more. The solvent is preferably designed to have a high boiling point of 100° C. to 200° C. in order to obtain uniform application while considering the evaporation rate.

The content ratio of each component in the composition is usually 10 to 30% (A) component, 2 to 10% (B) component, and 10 to 50% (D) component of the dry weight of the composition. It is preferable that the remaining 60 to 90% be the remaining 60 to 90%.

When component (A) is less than 10%, it is difficult to apply the composition smoothly to the substrate and the developability is poor, and when it is more than 30%, the viscosity tends to be high and coating becomes difficult.

If component (B) is less than 2%, the solubility in the exposed area will be insufficient and developability will be poor; if it is more than 10%, the photosensitivity will be high and the developability of fine line areas will be poor due to slight light wraparound etc. There is a tendency to become like this.

If component (C) is less than 10%, sufficient optical density for a color filter cannot be obtained, and if it is more than 50%, transparency tends to decrease.

If component (D) is less than 60%, the viscosity will be high and it will be difficult to obtain a uniform coating film, and if it is more than 9%, the viscosity will be low and it will be difficult to obtain a coating film of sufficient thickness.

Other additives may be mixed into the photosensitive resin composition for color filters of the present invention in order to provide it with further auxiliary functions. For example, a smoothing agent for imparting uniform coating properties, a silane coupling agent for enhancing adhesion to the substrate, etc. may be added.

The photosensitive resin composition for color filters of the present invention can be obtained by mixing the above-mentioned components at the mixing ratio as described above, preferably under stirring.

The photosensitive resin composition for color filters of the present invention is preferably subjected to a filtration treatment to remove undissolved coarse particles or foreign matter. The filtration treatment can be carried out under pressure using, for example, a filter medium with a pore size of 1 μm or less.

A color filter using the photosensitive resin composition for color filters of the present invention is produced, for example, as follows.

The photosensitive resin composition of the present invention is applied to a substrate such as glass using a spin method or the like, and the solvent is removed by heating and drying. Next, a negative mask is applied to the coating film on the base material thus obtained and irradiated with light. Next, the uncured areas are washed away by processing with a developer containing an alkaline agent. Rinse thoroughly and dry to remove color filters.

Example The present invention will be explained in more detail based on examples.

Production Example (Production of Novolak Resin) In a flask, 68.4 g (0.3 mol) of bisphenol A and 30.0 g (0.3 mol) of p-tert-butylphenol were added.
After charging 2 moles), 200% acetic acid was added, and then 35.3 g (0.44 moles) of 37% formalin was added.
The mixture was heated to 105-107°C and stirred for 6 hours.

After cooling, the reaction solution was added to a large amount of water and stirred,
Filtered. The resulting cake was again added to a large amount of water containing ammonium bicarbonate to neutralize it, and then the cake was washed with water and dried under reduced pressure below 40'C. The obtained novolak resin has a weight average molecular weight of 3400 and a number average molecular weight of 120.
0, it was a white resin.

Example 1 20 g of novolac resin obtained in Production Example and 6 g of 1,2-naphthoquinone diazide-5-sulfonyl triester of 2.3.4-trihydroxybenzophonone, Neo
zapon Green 975 (BASF) 10
g (equivalent to 27.8% of the solid content) was weighed out, transferred into 671 g of ethyl cellosolve acetate, and stirred to dissolve.

Pressure filtration was performed through a 0.2μ membrane filter to obtain a photosensitive resin composition for a green color filter of the present invention.

Application Example 1 Glass was used as a transparent substrate, which was cleaned with neutral detergent, water, and alcohol, and dried. The photosensitive resin composition of the present invention obtained in Example 1 was applied to this glass using a spin coater at 200 rpm for 10 seconds, and the temperature was 100°C.
and dried for 10 minutes. Next, a mask (Test Chart, manufactured by Toppan) was placed on a mask aligner (manufactured by Mikasa, Model MA-10), and the pattern was exposed for 30 seconds. Subsequently, development was performed at 25° C. for 130 seconds in a 2.38% solution of tetramethylammonium hydroxide. It was thoroughly washed with water and dried at 180°C for 20 minutes. A fine green pattern of 6.5 μm was obtained. This item showed no deformation.

Example 2 and Comparative Examples 1 to 3 Other novolac resins were manufactured according to the manufacturing example, and evaluated in the same manner as in Example 1 and Application Example 1. Table 1
It was like that.

Example 3 20g of novolac resin obtained in Example 2 and Neo-z
A photosensitive resin composition for a red color filter was obtained by processing according to Example 1, except that 10 g of apon Red 365 (BASF) was used.

Example 4 In Example 1, the dye was Neozapon Blue.
Example 1 except for changing to 807 (BASF) 10g
The same treatment as above was carried out to obtain a blue photosensitive resin composition for a color filter.

Effects of the Invention A photosensitive resin composition was obtained which required a short manufacturing process, was water-developable, and provided a color filter with high definition and high durability.

Patent applicant: Nippon Kayaku Co., Ltd.

Claims (1)

[Claims] 1. (A) a novolac resin obtained by polycondensing a phenol component containing 50 mol% or more of bisphenol A and an aldehyde component as an alkali-soluble resin (B) a photo-modified dissolution inhibitor (C) (D ) A photosensitive resin composition for color filters containing a dye (D) that is soluble in the solvent and compatible with (A) the resin.